SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f92c85120f2c3cfd45f574bbfc0bd6817ff3a893543426ccda9fbccd731a3a1f' 
  AND token = 'KSXMUBNWEJVgYCfr+E05E9F4Nf0nhQC42gA/x/cq1pE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}